Method of manufacturing plated component

ABSTRACT

A method of manufacturing a plated component includes: a molding step of molding a substrate including a plurality of plateable portions, which are spaced apart from each other, and coupling portions, which couple the plateable portions to each other, the substrate being a nonconductive plastic molding; an electroless plating step of forming a conductive coating on the plateable portions; and an electrolytic plating step of conducting different electrolytic plating processes on the plateable portions on which different metallic coatings are to be formed.

BACKGROUND

The present invention relates to a method of manufacturing a plated component including plateable portions on which different metallic coatings are formed.

For example, vehicle decorative components having a metallic appearance include a radiator grille, a back panel, and a fog cover mounted on automobiles. These vehicle decorative components are manufactured by forming a plated coating on a plastic substrate. The plated coating includes multiple layers of metallic coatings. As a method of manufacturing such a plated component, a plating method has been proposed in which electroless plating is conducted on a substrate to form a conductive coating and to impart conductivity, and electrolytic plating is subsequently conducted to form multiple layers of metallic coatings.

Conventionally, to manufacture a plated component that includes multiple plateable portions on which plated coatings having layer structures different from each other are formed, multiple plateable members are separately molded, and the plateable members are subjected to different kinds of electrolytic plating to form plated coatings having layer structures different from each other. Subsequently, these plateable members are each mounted on, for example, an automobile. Alternatively, the plateable members are previously assembled to make an integral whole, and the assembled component is mounted on an automobile.

This method, however, increases the number of parts and requires different kinds of electrolytic plating to be conducted on different plateable members. The method also requires a step such as mounting each of the plateable members to, for example, an automobile. This undesirably complicates the manufacturing process of the plated component.

In this respect, Japanese Laid-Open Patent Publication No. 59-126790 discloses a multi-color plating method. In this method, a non-electroless plating insulation paint is applied to a substrate to divide the surface of the substrate into two or more uncoated sections. Subsequently, the uncoated sections are subjected to electroless plating to make the uncoated sections conductive. After that, the uncoated sections are each subjected to different electroplating. This forms different metallic coatings on the uncoated sections (plateable sections) of one substrate.

With the multi-color plating method disclosed in Japanese Laid-Open Patent Publication No. 59-126790, a non-electroless plating insulation paint needs to be applied to the substrate to divide the substrate into multiple plateable sections. The addition of the above-described process undesirably complicates the manufacturing process.

SUMMARY

Accordingly, it is an objective of the present invention to provide a method of manufacturing a plated component that is capable of easily manufacturing a plated component that includes multiple plateable portions on which different metallic coatings are formed.

To achieve the foregoing objective, a method of manufacturing a plated component is provided that includes a molding step, an electroless plating step, and an electrolytic plating step. In the molding step, a substrate is molded that includes a plurality of plateable portions, which are spaced apart from each other, and coupling portions, which couple the plateable portions to each other. The substrate is a nonconductive plastic molding. The electroless plating step imparts conductivity to the plateable portions by forming a conductive coating on the plateable portions. The electrolytic plating step conducts different electrolytic plating processes on the plateable portions on which different metallic coatings are to be formed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a pretreatment step and an electrolytic plating step in a method of manufacturing a plated component according to a first embodiment.

FIG. 2 is a front view of the plated component according to the first embodiment.

FIG. 3A is a front view illustrating the relationship between a first hanger used in satin nickel plating step of the first embodiment and a substrate.

FIG. 3B is a front view illustrating the relationship between a second hanger used in bright nickel plating step of the first embodiment and the substrate.

FIG. 4A is a cross-sectional view of a first plateable portion, a conductive coating, and a first plated coating.

FIG. 4B is a cross-sectional view of a second plateable portion, the conductive coating, and a second plated coating.

FIG. 5 is a diagram illustrating a pretreatment step and an electrolytic plating step in a method of manufacturing a plated component according to a second embodiment.

FIG. 6A is a front view illustrating the relationship between a third hanger used in trivalent chromium plating step according to the second embodiment and a substrate.

FIG. 6B is a front view illustrating the relationship between the first hanger used in dark trivalent chromium plating step according to the second embodiment and the substrate.

FIG. 7A is a cross-sectional view illustrating a first plateable portion, a conductive coating, and a first plated coating.

FIG. 7B is a cross-sectional view illustrating a second plateable portion, the conductive coating, and a second plated coating.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

A method of manufacturing a plated component according to a first embodiment will be described with reference to FIGS. 1 to 4.

A plated component 10 of the present embodiment configures a radiator grille of an automobile. As shown in FIG. 2, the plated component 10 includes a nonconductive plastic molding, which is a substrate 12 in this embodiment. In the present embodiment, to simplify the illustration, the substrate 12 is rectangular as viewed from the front. In the following description, the longitudinal direction of the substrate 12 is referred to as a longitudinal direction L, and the transverse direction of the substrate 12 is referred to as a transverse direction S.

As shown in FIG. 2, the substrate 12 includes multiple plateable portions 14 a, 14 b and multiple coupling portions 16. The plateable portions 14 a, 14 b have the same waveform and are spaced apart from each other in the longitudinal direction L. Each of the coupling portions 16 couples the pair of plateable portions 14 a, 14 b that are adjacent to each other in the longitudinal direction L. Each coupling portion 16 couples the regions other than the plating surfaces of the plateable portions 14 a, 14 b, that is, the surfaces on which a conductive coating 20 and plated coatings 30 a, 30 b, which will be discussed below, are to be formed.

The plateable portions 14 a, 14 b are made of black ABS plastic. The coupling portions 16 are made of transparent polycarbonate. The plateable portions 14 a, 14 b and the coupling portions 16 are integrally formed by two-color molding.

As shown in FIG. 2, the first plateable portions 14 a are located every other row in the longitudinal direction L, and the second plateable portions 14 b are each located between the first plateable portions 14 a that are adjacent to each other in the longitudinal direction L.

First contacts 18 a project outward from both ends of each first plateable portion 14 a in the transverse direction S.

Second contacts 18 b project outward from both ends of each second plateable portion 14 b in the transverse direction S.

As shown in FIG. 4A, the conductive coating 20 made of nickel is formed on each first plateable portion 14 a. A first plated coating 30 a formed of multiple layers of metallic coatings is laminated on the conductive coating 20. The first plated coating 30 a includes a copper coating 32, a semi-bright nickel coating 34, a satin nickel coating 36 a, a micro-porous nickel coating (hereinafter, referred to as an MP nickel coating 38), and a trivalent chromium coating 40 (known as the white trivalent chromium coating), which are laminated in this order from the side corresponding to the conductive coating 20.

As shown in FIG. 4B, the conductive coating 20 made of nickel is formed on each second plateable portion 14 b. A second plated coating 30 b formed of multiple layers of metallic coatings is laminated on the conductive coating 20. The layer structure of the second plated coating 30 b differs from the layer structure of the first plated coating 30 a. The second plated coating 30 b includes the copper coating 32, the semi-bright nickel coating 34, a bright nickel coating 36 b, the MP nickel coating 38, and the trivalent chromium coating 40, which are laminated in this order from the side corresponding to the conductive coating 20.

That is, the satin nickel coating 36 a is provided in the first plated coating 30 a, whereas the bright nickel coating 36 b is provided in the second plated coating 30 b instead of the satin nickel coating 36 a.

A procedure of manufacturing the plated component 10 of the present embodiment will now be described.

In manufacturing the plated component 10, first, the above-described substrate 12 is integrally formed by two-color molding (molding step).

Next, as shown in FIG. 1, a known pretreatment step is conducted (S101 to S105) before conducting an electrolytic plating step on the substrate 12.

In the pretreatment step, first, a degreasing step (S101) is conducted to degrease the substrate 12. This removes grease and other substances attached to the surface of the substrate 12.

Subsequently, in an etching step (S102), the substrate 12 is etched using a solution of chromic acid and sulfuric acid to roughen (make uneven) the surface of the plateable portions 14 a, 14 b made of ABS plastic.

Subsequently, in a catalyst step (S103), a catalyst such as a PdSn complex is absorbed onto the surfaces of the plateable portions 14 a, 14 b. The catalyst causes electroless nickel to be precipitated and form the conductive coating 20.

Subsequently, in an accelerator step (S104), the adsorbed catalyst is activated.

Subsequently, in an electroless nickel plating step (S105), electroless nickel plating is conducted in an electroless nickel plating solution containing a reducing agent such as sodium hypophosphite to form a nickel coating, which is the conductive coating 20 in this embodiment, on the surfaces of the nonconductive plateable portions 14 a, 14 b. In the present embodiment, the electroless nickel plating step corresponds to the electroless plating step of the present invention.

Next, an electrolytic plating step is conducted (S106 to S111).

In the electrolytic plating step, first, a copper plating step (S106) is conducted. In the copper plating step (S106), terminals of a hanger (refer to FIG. 6A) are connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known copper plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the above-described hanger. This forms the copper coating 32 on the conductive coating 20 of the plateable portions 14 a, 14 b.

Subsequently, in a semi-bright nickel plating step (S107), the terminals of the hanger (refer to FIG. 6A) are connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known semi-bright nickel plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the above-described hanger. This forms the semi-bright nickel coating 34 on the copper coating 32 of the plateable portions 14 a, 14 b.

Subsequently, in a satin nickel plating step (S108), terminals of a first hanger 51 are connected to all the first contacts 18 a of the substrate 12 as shown in FIG. 3A, and the substrate 12 is immersed in a known satin nickel plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the first contacts 18 a using the first hanger 51. At this time, since the first hanger 51 is not connected to the second contacts 18 b, current supply to the second plateable portions 14 b is blocked. This forms the satin nickel coating 36 a only on the semi-bright nickel coating 34 of the first plateable portions 14 a. In the present embodiment, the satin nickel plating step corresponds to a first electrolytic plating process of the present invention. Additionally, the satin nickel coating 36 a corresponds to a first metallic coating of the present invention.

Subsequently, in a bright nickel plating step (S109), terminals of a second hanger 52 are connected to all the second contacts 18 b of the substrate 12 as shown in FIG. 3B, and the substrate 12 is immersed in a known bright nickel plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the second contacts 18 b using the second hanger 52. At this time, since the second hanger 52 is not connected to the first contacts 18 a, current supply to the first plateable portions 14 a is blocked. This forms the bright nickel coating 36 b only on the semi-bright nickel coating 34 of the second plateable portions 14 b. In the present embodiment, the bright nickel plating step corresponds to a second electrolytic plating process of the present invention. Additionally, the bright nickel coating 36 b corresponds to a second metallic coating of the present invention.

Subsequently, in a MP nickel plating step (S110), the terminals of the hanger (refer to FIG. 6A) are connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known MP nickel plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the above-described hanger. This forms the MP nickel coating 38 on the satin nickel coating 36 a of the first plateable portions 14 a and on the bright nickel coating 36 b of the second plateable portions 14 b.

Subsequently, in a trivalent chromium plating step (S111), the terminals of the hanger (see FIG. 6A) are connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known trivalent chromium plating solution (neither is shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the above-described hanger. This forms the trivalent chromium coating 40 on the MP nickel coating 38 of the plateable portions 14 a, 14 b.

A known chromate conversion coating step is then conducted to complete the plated component 10.

Cleaning steps are provided between these steps as required so that a chemical used in each step does not mix in the next step.

The method of manufacturing the plated component according to the present embodiment described above has the following operational advantages.

(1) The method of manufacturing the plated component 10 includes the molding step of molding the substrate 12, which is a nonconductive plastic molding. The substrate 12 includes the plateable portions 14 a, 14 b, which are spaced apart from each other, and the coupling portions 16, which couple the plateable portions 14 a, 14 b to each other. Additionally, the method includes the electroless plating step of forming the conductive coating 20 on the plateable portions 14 a, 14 b. The method also includes the electrolytic plating step in which different electrolytic plating processes are conducted on the plateable portions 14 a, 14 b on which different metallic coatings (the satin nickel coating 36 a and the bright nickel coating 36 b) are to be formed.

The method omits a step of applying the insulation paint before the electroless plating step since the plateable portions 14 a, 14 b are spaced apart from each other and are electrically insulated from each other. Thus, the plated component 10 including the plateable portions 14 a, 14 b on which different metallic coatings (the satin nickel coating 36 a and the bright nickel coating 36 b) are formed is easily manufactured.

(2) The electrolytic plating step includes the first electrolytic plating process of forming the satin nickel coating 36 a on the first plateable portions 14 a in a state in which an electric current is supplied to the first plateable portions 14 a and current supply to the second plateable portions 14 b is blocked. Additionally, the electrolytic plating step includes the second electrolytic plating process of forming the bright nickel coating 36 b on the second plateable portions 14 b in a state in which an electric current is supplied to the second plateable portions 14 b and current supply to the first plateable portions 14 a is blocked.

With this method, the satin nickel coating 36 a is formed only on the first plateable portions 14 a, whereas the bright nickel coating 36 b is formed only on the second plateable portions 14 b. The method allows for manufacturing of the plated component 10 that includes the first plateable portions 14 a, which have satin-like appearance by the formation of the satin nickel coating 36 a, and the second plateable portions 14 b, which have bright appearance by the formation of the bright nickel coating 36 b.

Second Embodiment

Hereinafter, a second embodiment will be described with reference to FIGS. 5 to 7.

The substrate 12 of a plated component 110 of the second embodiment is identical to that in the first embodiment. In the second embodiment, like or the same reference numerals are given to those components that are like or the same as the corresponding components of the first embodiment, and detailed explanations are omitted.

As shown in FIG. 7A, the conductive coating 20 made of nickel is formed on each first plateable portion 14 a. A first plated coating 60 a formed of multiple layers of metallic coatings is laminated on the conductive coating 20. The first plated coating 60 a includes the copper coating 32, the semi-bright nickel coating 34, the bright nickel coating 36 b, the MP nickel coating 38, the trivalent chromium coating 40, and a dark trivalent chromium coating 42, which are laminated in this order from the side corresponding to the conductive coating 20.

As shown in FIG. 7B, the conductive coating 20 made of nickel is formed on each second plateable portion 14 b. A second plated coating 60 b formed of multiple layers of metallic coatings is laminated on the conductive coating 20. The layer structure of the second plated coating 60 b differs from the layer structure of the first plated coating 60 a. The second plated coating 60 b includes the copper coating 32, the semi-bright nickel coating 34, the bright nickel coating 36 b, the MP nickel coating 38, and the trivalent chromium coating 40, which are laminated in this order from the side corresponding to the conductive coating 20.

That is, the first plated coating 60 a includes both the trivalent chromium coating 40 and the dark trivalent chromium coating 42, whereas the second plated coating 60 b includes only the trivalent chromium coating 40.

A procedure of manufacturing the plated component 110 of the second embodiment will now be described.

As shown in FIG. 5, before conducting the electrolytic plating step on the substrate 12, the pretreatment step that is the same as the pretreatment step of the first embodiment is conducted (S101 to S105).

Next, the electrolytic plating step (S106, S107, S109 a, S110, S111, and S112) is conducted.

First, the copper plating step (S106) and the semi-bright nickel plating step (S107) are performed by the same method as in the first embodiment.

Subsequently, in a bright nickel plating step (S109 a), the terminals of the hanger (refer to FIG. 6A) are connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known bright nickel plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the above-described hanger. This forms the bright nickel coating 36 b on the semi-bright nickel coating 34 of the plateable portions 14 a, 14 b.

Subsequently, the MP nickel plating step (S110) is performed by the same method as in the first embodiment.

Subsequently, the trivalent chromium plating step (S111) is performed by the same method as in the first embodiment. That is, as shown in FIG. 6A, a third hanger 53 is connected to all the contacts 18 a, 18 b of the substrate 12, and the substrate 12 is immersed in a known trivalent chromium plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the contacts 18 a, 18 b using the third hanger 53. This forms the trivalent chromium coating 40 on the MP nickel coating 38 of the plateable portions 14 a, 14 b. In the second embodiment, the trivalent chromium plating step corresponds to the first electrolytic plating process of the present invention. Additionally, the trivalent chromium coating 40 corresponds to the first metallic coating of the present invention.

Subsequently, in a dark trivalent chromium plating step (S112), the first hanger 51 is connected to all the first contacts 18 a of the substrate 12 as shown in FIG. 6B, and the substrate 12 is immersed in a known dark trivalent chromium plating solution (not shown). In this state, an electric current is supplied to the substrate 12 through all the first contacts 18 a using the first hanger 51. The dark trivalent chromium plating solution is a trivalent chromium plating solution to which a compound such as thiocyanate is added. At this time, since the first hanger 51 is not connected to the second contacts 18 b, current supply to the second plateable portions 14 b is blocked. This forms the dark trivalent chromium coating 42 only on the trivalent chromium coating 40 of the first plateable portions 14 a. In the second embodiment, the dark trivalent chromium plating step corresponds to the second electrolytic plating process of the present invention. Additionally, the dark trivalent chromium coating 42 corresponds to the second metallic coating.

A known chromate conversion coating step is then conducted to complete the plated component 110.

Cleaning steps are provided between these steps as required so that a chemical used in each step does not mix in the next step.

The method of manufacturing the plated component according to the second embodiment described above has the following operational advantage.

(3) The electrolytic plating step includes the first electrolytic plating process of forming the trivalent chromium coating 40 on all the plateable portions 14 a, 14 b in a state in which an electric current is supplied to all the plateable portions 14 a, 14 b. The electrolytic plating step also includes the second electrolytic plating process of forming the dark trivalent chromium coating 42 on the first plateable portions 14 a in a state in which an electric current is supplied to the first plateable portions 14 a.

With this method, first, the trivalent chromium coating 40 is formed on all the plateable portions 14 a, 14 b. Subsequently, the dark trivalent chromium coating 42 is formed only on the first plateable portions 14 a. The method allows for manufacturing of the plated component 110 that includes the second plateable portions 14 b, which have white bright appearance by the formation of the trivalent chromium coating 40, and the first plateable portions 14 a, which have black bright appearance by the formation of the dark trivalent chromium coating 42 on the trivalent chromium coating 40.

Modifications

The above-described embodiments may be modified as follows.

In the second embodiment, for example, after the trivalent chromium plating step (S111), all the second contacts 18 b may be removed. In this case, the operator may continue to use the third hanger 53 in the following dark trivalent chromium plating step (S112). This saves the trouble of having to replace the hanger.

The plated component of the present invention is not limited to the radiator grille of an automobile. The plated component may be embodied in other exterior components such as a back panel and a fog cover. The present invention may be applied to interior components and vehicle decorative components. 

1. A method of manufacturing a plated component, comprising: a molding step of molding a substrate including a plurality of plateable portions, which are spaced apart from each other, and coupling portions, which couple the plateable portions to each other, the substrate being a nonconductive plastic molding; an electroless plating step of imparting conductivity to the plateable portions by forming a conductive coating on the plateable portions; and an electrolytic plating step of conducting different electrolytic plating processes on the plateable portions on which different metallic coatings are to be formed.
 2. The method according to claim 1, wherein the electrolytic plating step includes a first electrolytic plating process of forming a first metallic coating on first plateable portions of the plateable portions in a state in which an electric current is supplied to the first plateable portions and a current supply to all the other plateable portions is blocked, and a second electrolytic plating process of forming a second metallic coating on second plateable portions of the plateable portions different from the first plateable portions in a state in which an electric current is supplied to the second plateable portions and a current supply to all the other plateable portions is blocked.
 3. The method according to claim 1, wherein the electrolytic plating step includes a first electrolytic plating process of forming a first metallic coating on all of the plateable portions in a state in which an electric current is supplied to all the plateable portions, and a second electrolytic plating process of forming a second metallic coating that is different from the first metallic coating on first plateable portions of the plateable portions in a state in which an electric current is supplied to the first plateable portions. 